Anomalous accelerations in spacecraft flybys of the Earth

Acedo, L.

doi:10.1007/s10509-017-3205-x

Cited by 7 publications

(4 citation statements)

References 74 publications

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“…In the context of this discussion we should also mention that similar anomalous accelerations are also found in several spacecraft flybys of the Earth [3]. In this case, they are only a 1.5 % of those found in the case of the Juno's flybys of Jupiter.…”

Section: Discussionsupporting

confidence: 66%

A possible flyby anomaly for Juno at Jupiter

Acedo

Piqueras

Moraño

2018

Advances in Space Research

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In the last decades there have been an increasing interest in improving the accuracy of spacecraft navigation and trajectory data. In the course of this plan some anomalies have been found that cannot, in principle, be explained in the context of the most accurate orbital models including all known effects from classical dynamics and general relativity. Of particular interest for its puzzling nature, and the lack of any accepted explanation for the moment, is the flyby anomaly discovered in some spacecraft flybys of the Earth over the course of twenty years. This anomaly manifest itself as the impossibility of matching the pre and post-encounter Doppler tracking and ranging data within a single orbit but, on the contrary, a difference of a few mm/s in the asymptotic velocities is required to perform the fitting.Nevertheless, no dedicated missions have been carried out to elucidate the origin of this phenomenon with the objective either of revising our understanding of gravity or to improve the accuracy of spacecraft Doppler tracking by revealing a conventional origin.With the occasion of the Juno mission arrival at Jupiter and the close flybys of this planet, that are currently been performed, we have developed an orbital model suited to the time window close to the * E-mail: luiacrod@imm.upv.es 1 perijove. This model shows that an anomalous acceleration of a few mm/s 2 is also present in this case. The chance for overlooked conventional or possible unconventional explanations is discussed.

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Section: Discussionsupporting

confidence: 66%

A possible flyby anomaly for Juno at Jupiter

Acedo

Piqueras

Moraño

2018

Advances in Space Research

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“…Previous studies also reported slightly larger values of about 4cm/yr (Stephenson, 1981). It was proposed that these astrophysical anomalies may have some cosmological origin or may call upon new physical driving mechanisms not taken into account by traditional Newtonian physics and General Relativity (Acedo, 2017).…”

Section: Introductionmentioning

confidence: 99%

Gravitational Weakening of Seismic Origin as a Driving Mechanism of Some Astronomical Anomalies

Rivera¹

2019

APR

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The anomalous increase of the astronomical unit, the mysterious secular increase of the lunar eccentricity and the flyby anomaly are important issues of modern astronomy. This study aims to determine the effect of earthquakes on the origin of these anomalies. Based on conventional physics, we found the existence of earthquake-induced gravitational weakening within the earth-moon-sun system and beyond. New equations of gravitation, including time dilation, are introduced that can explain the anomalous increase of the astronomical unit and the lunar orbit. A modified equation that includes the effect of massive quakes also explains the anomalous increase of the lunar eccentricity. Furthermore, the results of the present study can explain the flyby and Pioneer anomalies experienced by spacecraft during gravity assisted maneuvers. A modification of the 3rd Law of Kepler is also presented. Implications on the elliptic orbit of the earth, its reduced velocity and the occurrence of leap years are also discussed. Using the seismic-induced gravitational weakening model, probable trigger mechanisms of the faint young sun paradox and the Allais effect are also presented. An estimate of the age of the earth based on the observed values of the Hubble parameter and the USGS earthquake data for the past century is also presented. A new model of the seismic-driven expanding universe and a new equation to determine the expansion rate of galaxies and the universe is also proposed. The sudden earth’s retreat due to gravitational weakening and its implication on anomalous astronomical refraction and flight risk at night especially near the equatorial region, and its effect on the abrupt satellite orbital decay, spin and drift are also discussed. This study may also shed light on the occurrence of sinkholes and massive landslides. Finally, this study proposes a new equation that can explain the observed changes in the fine structure constant.

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“…For this reason, we expect that β(D = R) 1 were R is the radius of the central body (the Earth in the case of the flybys) because during a flyby the spacecraft comes very close to the surface of the planet. In other numerical and analytical studies on the flyby anomaly, it has been suggested that the interaction responsible for these anomalies should diminish exponentially with altitude over the surface of the Earth [44]. A fact that is supported by a statistical analysis by Jouannic et al [45] which showed that the largest values for the flyby anomaly are largely correlated with the time the spacecraft stays below an altitude of 2000 km.…”

Section: The Anomalous Increase Of the Orbital Eccentricitymentioning

confidence: 85%

“…where D is the distance from the central or source body to the orbiting planet, satellite or spacecraft, and Λ is a characteristic length scale that depends of the physical parameters of the source. We can assume that Λ is proportional to the radius of the central body, Λ ∝ R. For the case of the Earth, and following previous work on the flyby anomaly [44,45] it seems that the characteristic length for this anomalous interaction is not much larger than the radius of the Earth. For example, if we take Λ Earth = 2.5R Earth we find from Eq.…”

Section: The Anomalous Increase Of the Orbital Eccentricitymentioning

confidence: 92%

Angular Momentum and Energy Transfer in a Whitehead's Theory of Gravity

Acedo¹

2018

Preprint

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In this paper, we revisit a modified version of the classical Whitehead's theory of gravity in which all possible bilinear forms are considered to define the corresponding metric. Although, this is a linear theory that fails to give accurate results for the most sophisticated predictions of general relativity, such as gravity waves, it can still provide a convenient framework to analyze some new phenomena in the Solar System. In particular, recent development in the accurate tracking of spacecraft and the ephemerides of planetary positions have revealed certain anomalies in relation with our standard paradigm for celestial mechanics. Among them the so-called flyby anomaly and the anomalous increase of the astronomical unit play a prominent role. In the first case the total energy of the spacecraft changes during the flyby and a secular variation of the semi-major axis of the planetary orbits is found in the second anomaly. For this to happen it seems that a net energy and angular momentum transfer is taken place among the orbiting and the central body. We evaluate the total transfer per revolution for a planet orbiting the Sun in order to predict the astronomical unit anomaly in the context of Whitehead's theory. This could lead to a more deeply founded hypothesis for an extended gravity model.

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Anomalous accelerations in spacecraft flybys of the Earth

Cited by 7 publications

References 74 publications

A possible flyby anomaly for Juno at Jupiter

A possible flyby anomaly for Juno at Jupiter

Gravitational Weakening of Seismic Origin as a Driving Mechanism of Some Astronomical Anomalies

Angular Momentum and Energy Transfer in a Whitehead's Theory of Gravity

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